Vacuum-producing method and means.



A.- H.-PFUND.

VACUUM PRODUCING METHOD AND MEANS.

Y APPLICATION FILED FEB. 26, 1914.

v PatentedJfilylS, 19 15 INVENTOR f AUGUST Errunn, or BALTIMORE! MARYLAND.

To allwhom it mayconcern:

Be it lmownlthat' I, AUGUST Prom), a

citizen oft-the United States, anda resident of Baltimorainthe State of Maryland,jhave invented a new and useful Improvement in vacuumProducing,Methods and Means, of

' j which the following is a specification.

7 invention relates tovvacuumproduc- Hing .methods and apparatus and particu- .larly tomethods of and means for restoring impaired vacuum in chambers or receptacles for. for 'accentuating .or increasing such c I vacuum as @a simple, inexpensive andefiective method g and means that shall be available and ready may be produced by means of p ps,- a

Thelobject of my invention isto provide 1 ,f;or use,,-whenever, needed, to remove .such

v gases as may; impair the vacuum in a chamher, either immediately after disconnection "from ia .pump or at anytime during service.

5 My; invention may be -utilizedeffectively and advantageously inconnection With any Lflapparatusrhavingr'a chamber ior-ichambers in fftaina highdegree of vacuum but 'it ;will be which it-is necessary or desirable to mainifound especially" useful. in connection with ivapor' lamps and rectifiersand otherappa-- ratu's embodying electrical. conductors and '30 yventionmay be advantageously applied is I viewgof, ar mercuryyvapor; rectifier and its electrodes: to ,be operated in a highly developed vacuumL; j t

{An example ofapparatus to WlllCh my in shown ,in the accompanying drawing, the single figure ot which is :adiagrammatic Y circuits havingim'y vacuum 7 restoring, or

i accentuating-"apparatus attached thereto. I 1 Th'eidrawing illustrates thebulb or con- .40 a may of a mercury vapor V rectifier which mine 7 formed of either glassror metal and be provided with electrodes for connection supply d workfcircuitsin the us manner.

its circuit connections-is unnecessary, both because such-apparatus is well'known in the art and because the rectifier is shown merely as an exampleofvacuumi apparatus in general and Without restrictive intent. ,At-'

tached tothe bulb or container 1 is an auxiliaryqbulb, or container 20f glass or metal aving an electrodes3,Qpreferably, but not necessarily, of iron in its upper end, and an electrode 4, consisting of a body of as-absorbingqmaterial,,inyits bottom. i have I a Specification oflLettersI'atent; 1 ppncam filed February 26,1914.. Seria1No.821, 2 3 3.

' Further descriptionf th rectifier;

' vncnnurrtonucrnamnrnon AND MEANS.

Patented July 13, 1915;

found that comminuted charcoal, such, for

example, as cocoanut charcoal, is ag satisfactory gas-absorbing material but other materials, such, for example, as platinum black may be employed, if desired. The auxiliary small piece of platinumyor other suitable wire 8 having terminals brought to the outside and in electrical connection with electrode 3. The electrode 8 may be heated to incandescence by a battery of dry cells or other convenient source 9. The electrode 8 1s hereinafter called the Wehneltlelectrode. c a

secondary winding 5 of a transformer 6, the

fThe terminals 3 and 4 are connected tothe ,cpntainer also has in it, near electrode 3, a a

primary winding? ofwhichmay be supplied from, any suitablesourcer If my: apparatus is: used with a vapor'rectifier, the primary. w nding 7 may be supplied from the source to which the rectifier is connected."

The ratio of transformationwill be such that the secondary winding shall provide 1 from- 1000 to 6000 volts, according to the size and characteristics of the apparatus as a whole, In orderto start the discharges between the electrodes 3 and 4 under certain conditions, may utilize the Wehneltielectrode; '8 by heatm'g it to incandenscence by means of current from the source 9,0r from any other suitablei'source. A 4

In order, to prevent the passage of charcoa'l dust.iromflthe auxiliary chamber 2 to the main chamber 1 and thepassage of mercury particles from the chamber 1 to the chamber 2,.the connecting tube 10 may be provided with an enlargement 11 in which is placed abody of glass wool or other suit- "able material that is sufliciently porous to serve as aneffective screen.

in using my apparatus, a-Ysuitable vacuum 1 at any desired suitablepoint and is operated, while a heavy electrical discharge is mamta-ined between theelectr'odes Sand 4: c-

. -until .the occluded gases are expelled from;

the charcoal. Then the discharge isstopped and the tube is highly exhausted. The

{pump may then be sealed off from the chamber 1 by sealing off the connection, and

-p ump 1s "connected v to the mainichamber 

